Just two of nine coal barges that were pinned against the dam after the Christmas night accident were fully afloat as of Wed., Jan. 2. | Photo by Mark R. Long

A seventh coal barge has sunk and salvage operations soon will be underway at the Falls of the Ohio, a week after a line of the coal carriers broke away in a crash at the Second Street bridge, the Coast Guard said Wednesday.

The towing vessel Debbie Graham was pushing upstream 15 barges, which carry 1,500 to 1,800 tons of coal each, when it went off course and struck the bridge. Six of the barges were recovered and nine drifted downstream to be pinned against the dam, said Lt. Cmdr. Michael Metz, a Coast Guard spokesman.

The cause of the incident, which took place downstream from Louisville’s drinking-water intakes, is under investigation. Metz declined to elaborate or estimate how long the probe could take. The Debbie Graham’s owner, Tennessee Valley Towing, will be responsible for the recovery costs. The Paducah company didn’t respond to messages seeking comment.

One of the sunken barges has blocked a gate bay in the dam, which would prevent the Army Corps of Engineers from closing the gate, according to Shawn Kenney, the Corps’ Louisville District assistant operations manager. Vessel traffic currently is only permitted in daylight hours between Twelve Mile Island and the McAlpine Locks and Dam, the Coast Guard said.

Metz said salvage operations would start soon.

“Tennessee Valley Towing hired two salvage crews to come in and assess the situation and their equipment should be arriving as early as this afternoon or this evening,” he said. The firms Big River Shipbuilders Inc. and McKinney Salvage & Heavy Lift will jointly conduct the operation. A spokesman for Vicksburg, Miss.-based Big River said the companies would soon assess the site and plan the salvage.

The incident is the Debbie Graham’s second in less than a year: In April, the vessel lost maneuverability when a piece of its steering mechanism broke.

Even though total coal shipments have been declining in the United States, the share of that coal transported by barge rose in 2017, accounting for 12 percent of shipments, up from 7 percent in 2008, according to the Energy Information Administration.

Last year, more than 4,800 vessels with total tonnage of over 54 million moved through the McAlpine locks, according to an Army Corps spokeswoman. A breakdown of coal, chemical and other shipments passing through Louisville wasn’t immediately available. Just over six million tons of coal passed Cincinnati in 2018, according to the OKI Regional Council of Governments.

This article has been updated with details on the companies hired for the salvage operation.